1. Field of the Invention
The present invention relates to a method for detecting a media touch of a print head of an inkjet printer and an inkjet printer configured to perform the method of the present invention.
2. Description of Background Art
In a known inkjet printer, a print head scans along a recording medium, while ejecting ink drops from nozzles, usually arranged in a predetermined nozzle array. The ink drops are ejected corresponding to a predetermined pattern, thereby forming an image on the recording medium. Of course, the inkjet technology is not limited to ejecting ink. Other fluids may be ejected as well.
Further, it is known that the print head may touch the recording medium, while the print head scans along the recording medium. As a result, ink from a first nozzle having a first color may be smeared over an outer surface of the print head and may enter another nozzle of the print head, which other nozzle is arranged for ejecting ink of another color. Thereby, the smeared ink will pollute the other nozzle. Also, dirt like dust, paper fibers and the like may enter and pollute the nozzles. Due to the dirt, ink drops may be misdirected or the nozzle may become obstructed. On the other hand, the image on the recording medium may be smeared by the print head touching the recording medium.
In a known method, the print head is provided with a sensor system for sensing malfunctioning of nozzles. In the known method, printing an image may be cancelled or interrupted for cleaning, when it is detected that a relatively large number of nozzles is malfunctioning, irrespective of the cause of the malfunctioning. However, a corrective action may depend on the cause of the malfunctioning. Moreover, malfunctioning nozzles may become functioning again, if not operated for a certain period of time, depending on the cause of malfunctioning. In the latter case, printing does not need to be interrupted or cancelled. In the case of a medium touch, however, printing may need to be cancelled, since the print quality of the print is likely to be insufficient. Moreover, the print head probably needs cleaning in order to prevent (permanent) damage to the print head.